The Spotted lanternfly has it made. It has reached critical mass in New York City, Westchester and Rockland County, has made it up to Putnam Valley and Orange. It’s only a matter of time before the unlimited feeding frenzy begins in the forests and back yards of the Mid Hudson Valley. This invasive insect from Asia has an unlimited supply of food, feeding on more than over 100 different species of plants and trees.
When these insects are ready to lay eggs, their favorite food, Ailanthus altissima, or Tree of Heaven, is in plentiful supply for them. After the eggs are laid, the adults are free to leave the Tree of Heaven and return with their offspring to feed on keystone trees such as Maple, Black Walnut, Birch, Willow, Oak, Sycamore, Tulip Poplar, Apple, Cherry, Pine, Hickory, Serviceberry, Sassafras, Dogwood, American Beech, White Ash, and Plum! They have free reign with unlimited food, reproduction, and no predators. Why is the spotted lanternfly here?
Ailanthus, the Tree of Heaven
In the late 1700’s, trees were a rare commodity in burgeoning cities like Philadelphia and New York. On the lookout for trees that could survive in densely populated areas, horticulturists discovered the ailanthus tree in Asia and raved about its rapid growth and attractive appearance. The exotic, ornamental “Tree of Heaven” caught on big. By the mid-1800’s, it was being sold in nurseries across the country. A hundred years later, its invasive nature became more apparent as it spread rapidly, particularly in disturbed urban and suburban areas. By the turn of this century, the Norway Maple and the Tree of Heaven outnumbered native trees in urban and suburban cities. Despite being labeled as invasive and widely discouraged or prohibited, you can still buy it at nurseries today. And currently, the spotted lanternfly that evolved in Asia alongside the ailanthus, has found its way over here, and there’s no stopping it.
Identifying Ailanthus
Ailanthus trees are all over the Hudson Valley. They are in Kingston, Newburg, Poughkeepsie, and even small hamlets like Rosendale, Cold Spring, and Woodstock. They have leaf structure similar to Black Walnut or Sumac. The easiest way to identify ailanthus is to mash up a leaf with your fingers. If it has a foul odor, you’ve found one.
They proliferate in back yards, parks, empty lots, and along roadsides, where the utilities routinely cut them so as not to interfere with the power lines. This method of control only encourages them. When an ailanthus tree is cut down, the roots can no longer communicate with the canopy. The food supply from the leaves abruptly stops, the roots go into shock and begin to sprout from the remaining roots and the stem to produce more leaves.
If you try to cut down an ailanthus tree, you are only making it worse. The roots must be dug up with the rest of the tree or it will continue to sprout more shoots. Furthermore, the trees communicate with each other, so if you cut down too many of them at once, the mature females send out a truly amazing amount of seeds. We saw this happen.
Managing Ailanthus and Its Impact
If you have ailanthus trees on your property, there are no easy answers. Before you call us, look around and identify how many there are in your general vicinity. If you have a few of them and they are not part of a larger group, we could do something about it. If they are part of a larger stand, especially if the others are not on your property, all you can do is dig up the saplings when they show up.
Given the extensive spread and impact of Ailanthus and the spotted lanternfly, managing these invasive species is crucial. Regular monitoring and proactive removal strategies are necessary to prevent further encroachment and mitigate damage. As always, staying informed and prepared is key to controlling its spread and protecting local ecosystems.